In vitro response of groundnut (Arachis hypogaea L.) genotypes for tolerance to osmotic stress

Abstract

The present work was carried out to assess the tolerance of groundnut genotypes to induced osmotic stress usingtwenty-six groundnut genotypes along with four checks. The osmotic stress was induced using polyethylene glycol (PEG-6000) and the genotypes were treated with three different levels of PEG (0, -3 and -6 bars) in the laboratory using two factorialcomplete randomized design with two replications during 2020-21. Significant differences were observed among genotypesand PEG levels for all the traits. There was significant interaction between genotypes and PEG levels for all the traits.Germination and seedling traits decreased with the increase in PEG concentration and the genotypes exhibited differentialresponse to induced osmotic stress tolerance. The components of genetic variation for different traits under in vitroconditions revealed the existence of greater magnitude of variation for the all the traits and especially variation was greater at-6 bars of PEG concentration and there was significant differences among the genotypes. The PCV, GCV, heritability andGAM varied from low to high across the traits at different levels of PEG. The traits showing higher heritability coupled withhigh GAM indicated the possibility of improving these traits by selection. Seed germination was significantly affected by theosmotic potential induced by PEG in all the groundnut genotypes under the study. Seeds germinated more often and vigorouslyunder mild stress (0, -3 bars) than heavy stress (-6 bars) of PEG concentration. The genotypes,GND14(7.45 cm), GND 18(2.59 cm) and Dh 257 (1.93 cm) recorded highest shoot length at 0, -3 and -6bars of PEG levels, respectively. In the presentwork, the genotypes viz. K1812, ICGV15090, GND 6, GND 4 and GND 10 proved to be having osmotic stress tolerance.